Radiant fluid heater encased by inner transparent wall and radiation absorbing/reflecting outer wall for fluid flow there between

ABSTRACT

A fluid heater, capable of having a high energy density structure with an increased radiation receiving area, facilitating maintenance services and preventing intrusion of contamination substances, comprises a transparent internal pipe (11) which is open-ended at both ends and is positioned within an external pipe (12) of a fluid heating pipe unit (1). The fluid heating pipe unit (1) is provided with a fluid inlet (31) and a fluid outlet (32). The adjacent ends of the external pipe (12) and internal pipe (11) are connected to each other and sealed, and an electrical radiant heater (2) is arranged within the internal pipe (11) with a space (7) left therebetween. The ends of the electric heater (2) are removably supported by positioning members (91, 92). An inwardly directed radiation reflecting surface (12b) and/or a radiation absorbing material (12c) can be provided as part of the external tube (12).

TECHNICAL FIELD

The present invention relates to a fluid heater for resonance-heating afluid to be heated by radiant heat. More particularly, the inventionrelates to a fluid heater capable of appropriately carrying out heatingand temperature control, such as heating and temperature control ofetching solution and resist removing solution after cleaning wafers madeof silicon or the like in processes for manufacturing semiconductordevices, and heating and temperature control of oils for foodstuffswhile the fluid to be heated is being supplied.

BACKGROUND ART

An example of an appropriate use of a fluid heater is described withreference to a temperature control unit for a semiconductor wafertreating solution shown in FIG. 10. In FIG. 10, a treating bath 100 isfilled with treating solution 200. The treating solution 200 is forcedto flow in a teflon piping 400 by a pump 300, heated by a fluid heater500, filtered by a filter 600 to remove foreign substances contained inthe treating solution, and returned to the treating bath 100. Thetemperature of the treating solution 200 in the treating bath 100 isdetected by a sensor 700, and the controller 800 controls the fluidheater 500 so that the detected temperature approaches a presettemperature. In FIG. 10, numeral 510 denotes a box which incorporatesthe fluid heater 500, and numeral 900 denotes semiconductor wafers.

FIGS. 11(A) and 11(B) are respectively a perspective view and asectional view of a conventional fluid filter. Specifically, a pluralityof electric heaters 2 are provided on an external periphery of a fluidheating pipe unit 1 to heat fluid C introduced from an inlet pipe 31 anddischarged through an outlet pipe 32. In this example, the fluid heater2 comprises, in order from the inside, a fluid heating pipe unit 1, aclearance 7, an electric heater 2 formed with eight parallel memberssuch as nichrome wire, kanthal wire and others, and insulation material4.

In this case, the above described conventional fluid heater includes aproblem as described below. The fluid heater heats fluid by radiant heatand, in this case, a temperature increasing rate of fluid to be heatedby radiant heat is proportional to an energy density of absorptionwavelength band of heated fluid (penetration energy in a unit time in aunit area) if a radiation area is fixed, and is proportional to theradiation area if the energy density is fixed. In other words, theenergy density needs to be increased or the radiation area needs to beexpanded in order to raise the heating rate.

By the way, the higher the temperature of the electric heater 2 is, thehigher the energy density can be increased according to theStefan-Boltzmann law. However, unless the energy is absorbed only by thefluid heating pipe unit 1 when the electric heater 2 is set to a hightemperature, the temperature of the electric heater 2 rises, resultingin melting loss. Otherwise, even though the radiation area is expandedby increasing the number of members of the electric heater 2, theelectric heater 2 is short-circuited, resulting in melting loss. Inaddition, part of the radiant heat is radiated outwardly from theexternal periphery of the electric heater 2 and absorbed by theinsulation material 4 and therefore it does not contribute to theheating of the fluid.

On the other hand, the radiation area can be expanded to raise theheating rate but a larger fluid heating pipe unit 1 is required and thefluid heater needs to be a larger size. It is difficult to conduct heatto the portion of the fluid which flows in the central part of the fluidheating pipe unit 1, and consequently the heating rate is not raised.

Particularly in manufacturing semiconductor wafers, chemical solutionssuch as super-aqua-ammonia, sulfuric acid, hydrochloric acid andhydrofluoric acid are heated up to approximately 50°-150° C. in thefluid heater 500 for use in cleaning, etching and removing resist, buttechnologies in relation to corrosion resistance of the fluid heater 500and a low degree of contamination of heated chemical solution areunknown.

For example, an embodiment disclosed in the Patent ApplicationDisclosure No. 116246-1986 is a fluid heater differing from the abovedescribed prior art. Though not shown, the configuration of thisembodiment is such that a fluid heating pipe unit is provided on theexternal periphery of the electric heater. Specifically, this fluidheater comprises an electric heater serving as an infrared radiationmember and crystal glass forming an internal pipe of the fluid heatingpipe unit which are integrated. In such configuration, when the infraredradiation member is to be replaced, substances adhering to newcomponents are brought into the passage. For cleaning new components,the passage is exposed to the outside and there is a possibility offoreign substances which may intrude into the passage from an externalatmosphere even though new components are cleaned. A treating solutionfor wafers made of silicon or the like in semiconductor devicemanufacturing process needs to be filtered in a clean room to removeforeign substances contained in the solution, and therefore workaccompanying intrusion of foreign substances into the passage should beavoided. In addition, a chemical solution always leaks whenever thefluid heater is mounted and demounted, and the leakage can adhere toother components and an operator's body to result in a cause ofcorrosion and hazard to health. To prevent such leakage, the chemicalsolution should be removed in advance from the fluid heating pipe unit,which is a troublesome work. Fluids for etching and removing the resistare contaminated due to stains of devices after repeated use andtherefore should be periodically renewed by replacing them with freshfluids. In this case, the internal tube of the fluid heating pipe unit,which has a high temperature, is directly exposed to a low temperatureunheated fluid and thus is subjected to a large thermal impact, and thiswill therefore be a cause of remarkable reduction of the service life.This tendency is further increased in the configuration shown in FIGS.11(A) and 11(B). In other words, the electric heater 2 surrounded byinsulation material 4 maintains a high temperature for a long time evenafter the current supply has been stopped. The inventors of the presentinvention have confirmed that, if fluid C is removed and new unheatedfluid C is introduced into the heating pipe, this new fluid C is boiledon the surface of the heating pipe 1 to produce a great volume of vaporand the fluid heating pipe unit 1 would be broken by thermal impact dueto boiling and vapor pressure.

DISCLOSURE OF THE INVENTION

The first object of the present invention made in view of the abovedescribed problems of the prior art is to provide a fluid heater whichhas a high energy density structure and an increased radiation receivingarea. In addition, the second object is to provide a fluid heater whichfacilitates maintenance services and excels in prevention of intrusionof contamination sources.

To attain the above first object, the fluid heater in accordance withthe present invention can have a fluid heating pipe unit, which is madeof a transparent member, provided on the external periphery of theelectric heater and an inwardly faced reflection member provided on theexternal periphery of this fluid heating pipe unit.

Alternatively, the fluid heating pipe unit provided on the externalperiphery of the electric heater can be constructed with a transparentmember at the electric heater side and an inwardly faced reflectionmember as the external side.

In addition, this fluid heating pipe unit can be formed with a radiantheat absorbing member between the outside of the fluid heating pipe andthe inwardly faced reflection member.

Moreover, the electric heater can be U-shaped and the fluid heating pipeunit can be formed in a semispherical shape in which a reflector plateis provided and this U-shaped electric heater can be housed in aconcaved space of the semispherical fluid heating pipe unit.

The reflection surface of the inwardly faced reflection member on theoutside of the fluid heating pipe unit and the reflection surface of theinwardly faced reflection member provided on the external periphery ofthe radiant heat absorbing member are formed with a light reflectivefilm made of gold, aluminum, tin oxide, indium, or chromium.

To attain the above second object, the fluid heater in accordance withthe present invention has an electric heater which is a quartz glasstube type infrared ray heater, a fluid heating pipe unit which consistsof a transparent quartz glass tube at the electric heater side and afluororesin tube, which is a radiant heat absorbing member at theexternal side, whereby both ends of this quartz glass tube are fittedinto holes provided in both end closing walls of the fluororesin tube.The cross section of the external profile of the fluid heating pipe unitcan be polygonal.

The fluid heater is arranged in a housing, which can be inwardly coveredwith a light reflection film made of gold, aluminum, tin oxide, indiumor chromium.

In the structure as described above, radiant heat from the electricheater is basically radiated to the fluid heating pipe unit to heatfluid. Fluid penetrating radiant heat, which has not contributed to theinitial heating of the fluid, penetrates the outside of the fluidheating pipe unit and is reflected by the inwardly faced reflectionmember which is externally provided in an annular shape, then penetratesagain the outside of the fluid heating pipe unit to be re-radiated intothe fluid, whereby the fluid is further heated.

Fluid penetrating radiant heat is reflected into the fluid withoutpenetrating the outside of the fluid heating pipe unit to further heatthe fluid when the outside of the fluid heating pipe unit is formed asthe inwardly faced reflection member. When fluid penetrating radiantheat is absorbed by the radiant heat absorbing member on the outside ofthe fluid heating pipe unit, the absorbed radiant heat subsequentlyfurther heats the fluid as conduction heat.

Since the fluid heating pipe unit is formed with anticorrosive materialswhich are a quartz glass tube and a fluororesin tube, theanticorrosiveness of the fluid heating pipe unit and the lowcontaminativeness of fluid to be heated are improved. The electricheater formed as a quartz glass type infrared ray heater withstands hightemperatures, and maintainability is improved.

In addition, the reflection surface of the inwardly faced reflectionmember or the reflection surface of the inwardly faced reflection memberprovided on the external periphery of the radiant heat absorbing memberis formed as a light reflection film made of gold, aluminum, tin oxide,indium or chromium to prevent leakage of the penetrating radiant heatand to reflect the radiant heat into the fluid, thus making the radiantheat further contribute to the heating of the fluid.

Moreover, an internal pipe of a transparent fluid heating pipe unit,which is open-ended at both ends, can be disposed in an external pipe ofa fluid heating pipe unit, which is provided with a fluid inlet and afluid outlet in the pipe wall and open-ended at both ends, with a spaceleft between the internal wall of the external pipe and the internalpipe of the transparent fluid heating pipe unit. In addition, both endsof these external and internal pipes can be connected to each other andsealed, an electric heater can be arranged in the internal pipe with aspace left therebetween and both ends of this electric heater can besupported by supporting members.

The U-shaped electric heater can be housed in the U-shaped space formedby the semispherical fluid heating pipe unit, this fluid heating pipeunit can be arranged in a housing and both ends of the U-shaped electricheater can be supported by the supporting members on the cap provided onthis housing.

This configuration allows the removal and replacement of only theelectric heater from/into the fluid heater and therefore the fluid neednot be removed from the fluid heating pipe unit when the heater is to bereplaced, maintenance is facilitated and intrusion of contaminativesubstances can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1(A) is a perspective view of a fluid heater of the firstembodiment in accordance with the present invention and FIG. 1(B) is asectional view along line 1B--1B of the fluid heater of FIG. 1(A),

FIG. 2(A) is a perspective view of a fluid heater of the secondembodiment in accordance with the present invention and FIG. 2(B) is asectional view along line 2B--2B of the fluid heater of FIG. 2(A),

FIG. 2(C) is a perspective view of a fluid heater of the thirdembodiment in accordance with the present invention and FIG. 2(D) is asectional view along line 2D--2D of the fluid heater of FIG. 2(C),

FIG. 3(A) is a perspective view of a fluid heater of the fourthembodiment in accordance with the present invention and FIG. 3(B) is asectional view along line 3B--3B of the fluid heater of FIG. 3(A),

FIG. 3(C) is a perspective view of a fluid heater of a modification ofthe fourth embodiment in accordance with the present invention and FIG.3(D) is a sectional view along line 3D--3D of the fluid heater of FIG.3(C),

FIG. 4(A) is a perspective view of a fluid heater of the fifthembodiment in accordance with the present invention and FIG. 4(B) is asectional view along line 4B--4B of the fluid heater of FIG. 4(A),

FIG. 5(A) is a perspective view of a fluid heater of the sixthembodiment in accordance with the present invention and FIG. 5(B) is asectional view along line 5B--5B of the fluid heater of FIG. 5(A),

FIG. 6(A) is a perspective view of a fluid heater of the tenthembodiment in accordance with the present invention and FIG. 6(B) is asectional view along line 6B--6B of the fluid heater of FIG. 6(A),

FIG. 7 is a perspective view of a fluid heater of the eleventhembodiment in accordance with the present invention,

FIG. 8(A) is a sectional view of a fluid heater according to the 12thembodiment, FIG. 8(B) is a front view of the end part of the electricheater of the fluid heater of FIG. 8(A),

FIGS. 8(C1) and 8(C2) are respectively a front view and a side view of acap of the electric heater of the fluid heater of FIG. 8(A),

FIGS. 8(D1) and 8(D2) are respectively a front view and a side view of afirst ring of the electric heater of the fluid heater of FIG. 8(A),

FIGS. 8(E1) and 8(E2) are respectively a front view and a side view of asecond ring of the electric heater of the fluid heater of FIG. 8(A),

FIG. 9(A) is a sectional view of a fluid heater according to the 13thembodiment, FIG. 9(B) is a front view of a cap of the fluid heater ofFIG. 8(A), and FIGS. 9(C1) and 9(C2) are respectively a front view and aside view of the ring of the fluid heater of FIG. 8(A),

FIG. 10 is a perspective view showing an example of appropriate use ofthe fluid heater, and

FIG. 11(A) is a perspective view of a conventional fluid heater and FIG.11(B) is a sectional view along line 11B--11B of the fluid heater ofFIG. 11(A).

BEST MODE FOR CARRYING OUT THE INVENTION

The best embodiment of a fluid heater in accordance with the presentinvention is described in detail below referring to the accompanyingdrawings.

FIG. 1(A) and FIG. 1(B) respectively show the first embodiment of thepresent invention wherein a fluid heating pipe unit 1 is provided on anexternal periphery of electric heater 2 and, in addition, a separateinwardly faced reflection member 5, having a gold reflection layer 5a onits interior surface, is mounted about an external periphery of thisfluid heating pipe unit 1. This fluid heating pipe unit 1 is roughlyformed with internal and external tubes 11, 12, each made of a quartzglass tube. Specifically, the fluid heating pipe unit 1 is provided witha fluid inlet pipe 31 and a fluid outlet pipe 32 at the right and leftends, and the electric heater 2 along the center axis in a space 71 inthe internal tube 11. It is confirmed in the experiments by theinventors of the present invention that, though there is air in thisspace 71, light is rarely absorbed by air and a greater part of radiantheat from the electric heater 2 is radiated into the fluid heating pipeunit 1 to contribute to the heating of the fluid.

FIGS. 2(A) and 2(B) respectively show a fluid heater according to thesecond embodiment which is provided with the fluid heating pipe unit 1on the external periphery of the electric heater 2. Differing from thefirst embodiment, the separate inwardly faced reflection member 5 is notprovided on the external periphery of the fluid heating pipe unit 1, butthe inwardly faced reflection member 12b is integrally formed on theoutside of the fluid heating pipe unit 1.

FIGS. 2(C) and 2(D) illustrate the third embodiment, wherein the outsideof the fluid heating pipe unit 1 can be formed with a radiant heatabsorbing member 12c such as, for example, a black-colored memberinstead of the inwardly faced reflection member 12b in FIGS. 2(A) and2(B).

FIGS. 3(A) and 3(B) show the fourth embodiment. The fluid heating pipeunit 1 is semispherically shaped, the electric heater side 11 of thefluid heating pipe unit 1 is formed with transparent material and theoutside is coated with a reflection member 12b. The U-shaped electricheater 2 is housed in the semispherical space of the fluid heating tubeunit 1 and its upper part is covered with a reflection plate 5.

FIGS. 3(C) and 3(D) show a modification of the fourth embodiment. Thefluid heating pipe unit 1 is semispherically shaped, the electric heaterside 11 of the fluid heating pipe unit 1 is formed with transparentmaterial and the outside is coated with a radiant heat absorbing member12c. The U-shaped electric heater 2 is housed in the semispherical spaceof the fluid heating tube unit 1 and its upper part is covered with areflection plate 5.

In the fifth embodiment shown in FIGS. 4(A) and 4(B), the electricheater 2 is a quartz glass type infrared ray heater. The fluid heatingpipe unit 1 incorporates this quartz glass type infrared ray heater. Thefluid heating pipe unit 1 is provided with a quartz glass tube 11 at thequartz glass type infrared ray heater 2 side, an external fluororesintube 12d and sealing members 6, and the quartz glass tube 11 isfitted-to the holes of the closing walls of both ends of the fluororesintube 12d with sealing members 6.

FIGS. 5(A) and 5(B) show the sixth embodiment wherein the outside of thefluid heating pipe unit 1 is square-shaped to improve the stability ofthe fluid heater itself, though the outside of the fluid pipe unit 1 iscylindrically shaped in the fifth embodiment. Various modes of thisoutside profile are available because of polygonal cross section.

Since contamination substances adhere to the flow passage if there isunevenness in the flow passage, the surface of the fluororesin tube 12ashould be flat. Unevenness appears on the cut surface which is usuallymade by cutting but the tube 12a can be obtained as an injection-moldedproduct with high flatness free from pin holes by using fluororesin soldwith the brand name SAITOP by Asahi Glass Co., Ltd. For a fluid to beheated which is a hydrofluoric acid based reagent, the flow passageshould be made of fluororesin. SAITOP fluororesin can be coated on thesurface of quartz glass, and the flow passage side surface of the quartzglass tube 11 can be coated with a layer 11a of SAITOP fluororesin.Since the light transmission factor of SAITOP fluororesin from thevisible zone to the infrared ray zone is 95-96%, a thin film coating ofseveral hundred angstroms to several ten microns is enabled andsimultaneously the coating of SAITOP fluororesin on the flow passageside surface of the quartz glass tube 11 does not hinder transmission oflight.

The reflection surfaces of the inwardly faced reflection member 5 shownin the first embodiment can be a gold layer 5a, while the reflectionsurface of the inwardly faced reflection member in the second embodimentcan be a gold layer 12b. These reflection surfaces can be formed bylight reflection material such as aluminum, tin oxide, indium, chromiumor the like, instead of gold (the seventh and eighth embodiments).

An inwardly reflection member can be additionally provided on theexternal periphery of the external radiant heat absorbing member 12cshown in the third embodiment and this reflection surface can be formedby gold. Also in this case, the reflection surface can be formed bylight reflection material such as aluminum, tin oxide, indium, chromiumor the like (the ninth embodiment).

In the tenth embodiment, as shown in FIGS. 6(A) and 6(B), the fluidheater is arranged in the housing 8 which is inwardly covered with lightreflection material 12e such as gold, aluminum, tin oxide, indium,chromium or others so that the fluid heater is partly covered. As shownin FIG. 7, the housing can be a complete housing which wholly covers thefluid heater (the 11th embodiment). In this case, "inwardly faced" meansthat the reflection surface is faced to the inside where the fluidheater is arranged though this covering film is used on the externalsurface, internal surface or internal and external surfaces.

According to the above embodiments, basically, the fluid heating pipeunit 1 is provided on the external periphery of the electric heater 2 toheat fluid in the fluid heating pipe unit 1.

In case of the conventional fluid heater, a radiant heat component fromthe external periphery of the electric heater 2 is not radiated to thefluid heating pipe unit 1 and is only radiated to insulation material 4and therefore it is difficult for this radiant heat component tocontribute to heating of fluid. On the contrary, in cases of the abovedescribed embodiments, all radiant heat is basically radiated to thefluid heating pipe unit 1 and accordingly high speed heating is carriedout. In addition, since insulation material indispensable for theconventional fluid heater is omitted, the required space can be reduced.In other words, a high energy density structure is obtained for the sameheating calorie and the radiation receiving area is increased.

In addition, the fluid heating pipe unit 1 is made of quartz glass andfluororesin and therefore anticorrosiveness of the fluid heating pipeunit 1 can be improved. Since the fluororesin tube is made as aninjection molded product, its surface can be smoothed to avoid adhesionof fluid and contamination of heated fluid can be reduced.

The electric heater 2 is a quartz glass infrared ray heater, forexample, a halogen lamp which provides a filament temperature of 2000K˜3000 K, and can therefore be used at a high temperature approximatelytwo or three times the filament temperature of the nichrome wire, thelimit for which is approximately 1000K, and radiation light energy canbe increased 16-81 times. The existing reflection surfaces and thereflection surfaces separately provided can be formed by gold, aluminum,tin oxide, indium, chromium or a like material as a light reflectionfilm to prevent penetration of radiant heat to the outside.

In addition to the above, the electric heater 2 and the internaltransparent member 11 of the fluid heating pipe unit 1 are disposedopposing each other with a clearance 71 and both ends of the electricheater 2 are remountably fitted to the fluid heating pipe unit 1 withsupporting members. This structure is shown in detail in FIGS. 8(A) and9(A) as the 12th and 13th embodiments.

In FIG. 8(A), the electric heater 2 is a halogen lamp. In the quartzglass tube 21 having both ends formed to be flat after melting andcooling, a halogen element, inactive gas 23, and a tungsten filamentcoil 25 supported by a plurality of anchors 24 are sealed. A molybdenumfoil 26 is sealed inside each end 22, and the filament coil 25 and alead 27 inserted from the outside are connected to this molybdenum foil26. The details of the electric heater 2 and coupling of internal tube11 and external tube 12f are as described below.

The coupling relationship of the electric heater 2 and the internal tube11 is shown. The internal tube 11 incorporates the electric heater 2 andceramic rings 91 and 92, serving as supporting members, in sequence fromthe center and capped with silicone rubber bushes 93. Both ends 22 shownin FIG. 8(B) of the electric heater 2 are inserted into recesses 911 ofthe ceramic rings 91 shown in FIGS. 8(E1) and 8(E2). Leads 27 areconnected to an external power supply through the recesses 921 ofceramic rings 92 shown in FIGS. 8(D1) and 8(D2) and through holes 931 ofsilicone rubber bushes 93 shown in FIG. 8(C1) and 8(C2). Ceramic rings91 and 92 are used to provide a certain amount of clearance in thelengthwise direction of the internal tube 11 and also in the radialdirection while the electric heater 2 is housed in the internal tube 11.Therefore, ceramic rings 91 and 92 are loosely inserted into theinternal tube 11 as shown in FIG. 8(A). A difference of thermalexpansion between the electric heater 2 and the internal tube 11 isabsorbed by the above described clearance.

The coupling relationship of the internal tube 11 and the external tube12f is shown. A member 94 providing a hole through which the internaltube 11 is inserted at the center and a ferrule 95 to be used betweenthe internal tube 11 and the external tube 12f are prepared. A femalethread is provided at one end of the member 94 and a male thread isprovided on both ends of the external tube 12f. The internal tube 11 andthe electric heater 2 are fixed to the external tube 12f by fitting theferrule 95 into the groove of external tube 12f and thread-fitting themember 94 to the external tube 12f. The ferrule 95 is made of thermalresistant fluororesin and serves to seal fluid to be heated and absorbthe difference of thermal expansion of internal and external tubes 11and 12f.

According to the above embodiment, the electric heater 2 is remountablyinserted into the internal tube 11 and therefore fluid (chemicalsolution) need not be removed from the fluid heating pipe unit 1 whenthe electric heater 2 is to be replaced, maintenance services arefacilitated and intrusion of contamination substances into the flowpassage can be prevented. In addition, fluid to be heated is notdirectly exposed to a high temperature electric heater 2 and thereforethermal impact to the electric heater 2 can be reduced and its longerservice life can be ensured. The service life relates to the filamenttemperature, and the specified values are 3000 hours for 2800K and 1500hours for 3000K and the cycle of replacement is once per 0.5˜1 year. Aplurality of electric heaters are often used and the cycle ofreplacement will be further lengthened.

In case of the U-shaped electric heater, the fluid heater is arranged inthe housing 8 as shown in FIG. 9(A). The U-shaped electric heater 2 isfitted into the groove 951 of the rubber ring 95 via the through hole ofthe reflection plate 5 and the through hole 941 of the cap 94, and thering 95 is fitted to the cap 94 with bolt 952. Also in this case, theelectric heater 2 is easily remountable and inserted with a play owingto the elasticity of the rubber ring 95 serving as a supporting memberand therefore thermal expansion of the electric heater 2 is absorbed andwill not be damaged due to local load resulting from thermal expansion.This embodiment can apply to a pot for potable water.

INDUSTRIAL APPLICABILITY

The present invention provides a useful fluid heater capable of having ahigh energy density structure and an increased radiation receiving area,facilitating maintenance services and preventing intrusion ofcontamination substances. Particularly, the fluid heater in accordancewith the present invention is excellent as a fluid heater capable ofappropriately carrying out heating and temperature control, such asheating and temperature control of etching solution and resist removingsolution after cleaning wafers made of silicon or the like in processesfor manufacturing semiconductor devices, and heating and temperaturecontrol of oils for foodstuffs while the fluid to be heated is beingsupplied.

What is claimed is:
 1. A fluid heating device comprising:a transparentannular inner wall forming an internal space for receiving an infraredradiation heating member, said transparent annual inner wall havingfirst and second open ends; an annular outer wall spaced outwardly fromsaid transparent annular inner wall to form a fluid passagewaytherebetween; an infrared radiation heating member removably positionedin said internal space so that said infrared radiation heating membercan be removed from said fluid heating device without requiring thatsaid fluid passageway be opened; said infrared radiation heating member,when positioned in said internal space, being spaced from saidtransparent annular inner wall to form a clearance between said infraredradiation heating member and said transparent annular inner wall suchthat said infrared radiation heating member is at least partiallysurrounded by said transparent annular inner wall while avoiding directcontact between said infrared radiation heating member and saidtransparent annular inner wall; and a radiation reflection memberpositioned on the exterior of said annular outer wall so as to reflectinfrared radiation, which has passed from said infrared radiationheating member through said transparent annular inner wall, said fluidpassageway, and said annular outer wall, back through said annular outerwall into said fluid passageway.
 2. A fluid heating device comprising:atransparent annular inner wall forming an internal space for receivingan infrared radiation heating member; an annular outer wall spacedoutwardly from said transparent annular inner wall to form a fluidpassageway therebetween; an infrared radiations heating member removablypositioned in said internal space so that said infrared radiationheating member can be removed from said fluid heating device withoutrequiring that said fluid passageway be opened; said infrared radiationheating member, when positioned in said internal space, being spacedfrom said transparent annular inner wall such that said infraredradiation heating member is at least partially surrounded by saidtransparent annular inner wall while avoiding direct contact betweensaid infrared radiation heating member and said transparent annularinner wall; and a radiation reflection member positioned on the exteriorof said annular outer wall so as to reflect infrared radiation, whichhas passed from said infrared radiation heating member through saidtransparent annular inner wall, said fluid passageways, and said annularouter wall, back through said annular outer wall into said fluidpassageway; wherein said transparent annular inner wall is formed in anapproximately semispherical shape with a concave recess therein; andwherein said infrared radiation heating member is U-shaped with at leasta portion thereof being positioned in said concave recess.
 3. A fluidheating device in accordance with claim 2, further comprising areflection plate to close said concave recess.
 4. A fluid heating devicein accordance with claim 2, further comprising a housing enclosing saidtransparent annular inner wall and said annular outer wall, and anelastic supporting member on said housing for supporting both ends ofsaid U-shaped infrared radiation heating member.
 5. A fluid heatingdevice in accordance with claim 1, further comprising first and secondsupporting members loosely positioned within the internal space of saidtransparent annular inner wall with said first supporting member beingpositioned adjacent said first open end and said second supportingmember being positioned adjacent said second open end, said first andsecond supporting members supporting said infrared radiation heatingmember therebetween, said first and second supporting members providingclearance in the lengthwise direction of said transparent annular innerwall as well as clearance in the radial direction while the infraredradiation heating member is positioned within said internal space ofsaid transparent annular inner wall, and further comprising a first capclosing said first open end and a second cap closing said second openend.
 6. A fluid heating device in accordance with claim 1, wherein saidinfrared radiation heating member has first and second ends and agreater axial length than said transparent annular inner wall such thatsaid first and second ends of said infrared radiation heating memberextend outwardly from said first and second open ends of saidtransparent annular inner wall, and wherein said infrared radiationheating member can be removed from said fluid heating device througheither of said first and second open ends of said transparent annularinner wall.
 7. A fluid heating device comprising:a transparent annularinner wall forming an internal space for receiving an infrared radiationheating member, said transparent annular inner wall having first andsecond open ends; an annular outer wall spaced outwardly from saidtransparent annular inner wall to form a fluid passageway therebetween;and a quartz glass tube type infrared radiation heating member removablypositioned in said internal space so that said quartz glass tube typeinfrared radiation heating member can be removed from said fluid heatingdevice without requiring that said fluid passageway be opened; saidquartz glass tube type infrared radiation heating member, whenpositioned in said internal space, being spaced from said transparentannular inner wall to form a clearance between said quartz glass tubetype infrared radiation heating member and said transparent annularinner wall such that said quartz glass tube type infrared radiationheating member is at least partially surrounded by said transparentannular inner wall while avoiding direct contact between said quartzglass tube type infrared radiation heating member and said transparentannular inner wall; and wherein said annular outer wall reflectsinfrared radiation, which has passed from said quartz glass tube typeinfrared radiation heating member through said internal space, saidtransparent annular inner wall, and said fluid passageway, back intosaid fluid passageway.
 8. A fluid heating device comprising:atransparent annular inner wall forming an internal space for receivingan infrared radiation heating member; an annular outer wall spacedoutwardly from said transparent annular inner wall to form a fluidpassageway therebetween; and a quartz glass tube type infrared radiationheating member removably positioned in said internal space so that saidquartz glass tube type infrared radiation heating member can be removedfrom said fluid heating device without requiring that said fluidpassageway be opened; said quartz glass tube type infrared radiationheating member, when positioned in said internal space, being spacedfrom said transparent annular inner wall such that said quartz glasstube type infrared radiation heating member is at least partiallysurrounded by said transparent annular inner wall while avoiding directcontact between said quartz glass tube type infrared radiation heatingmember and said transparent annular inner wall; wherein said annularouter wall reflects infrared radiation, which has passed from saidquartz glass tube type infrared radiation heating member through saidinternal space, said transparent annular inner wall, and said fluidpassageway, back into said fluid passageway; wherein said transparentannular inner wall is formed in an approximately semispherical shapewith a concave recess therein; and wherein said quartz glass tube typeinfrared radiation heating member is U-shaped with at least a portionthereof being positioned in said concave recess.
 9. A fluid heatingdevice in accordance with claim 8, further comprising a reflection plateto close said concave recess.
 10. A fluid heating device in accordancewith claim 8, further comprising a housing enclosing said transparentannular inner wall and said annular outer wall, and an elasticsupporting member on said housing for supporting both ends of saidU-shaped quartz glass tube type infrared radiation heating member.
 11. Afluid heating device in accordance with claim 7, further comprisingfirst and second supporting members loosely positioned within theinternal space of said transparent annular inner wall with said firstsupporting member being positioned adjacent said first open end and saidsecond supporting member being positioned adjacent said second open end,said first and second supporting members supporting said quartz glasstube type infrared radiation heating member therebetween, said first andsecond supporting members providing clearance in the lengthwisedirection of said transparent annular inner wall as well as clearance inthe radial direction while the quartz glass tube type infrared radiationheating member is positioned within said internal space of saidtransparent annular inner wall, and further comprising a first capclosing said first open end and a second cap closing said second openend.
 12. A fluid heating device in accordance with claim 7, wherein saidquartz glass tube type infrared radiation heating member has first andsecond ends and a greater axial length than said transparent annularinner wall such that said first and second ends of said quartz glasstube type infrared radiation heating member extend outwardly from saidfirst and second open ends of said transparent annular inner wall, andwherein said quartz glass tube type infrared radiation heating membercan be removed from said fluid heating device through either of saidfirst and second open ends of said transparent annular inner wall.
 13. Afluid heating device comprising:a transparent annular inner wall formingan internal space for receiving an infrared radiation heating member; aquartz glass tube type infrared radiation heating member positioned insaid internal space and spaced from said transparent annular inner wallsuch that said quartz glass tube type infrared radiation heating memberis at least partially surrounded by said transparent annular inner wall;and an annular outer wall spaced outwardly from said transparent annularinner wall to form a fluid passageway therebetween, said annular outerwall absorbing infrared radiation, which has passed from said quartzglass tube type infrared radiation heating member through said internalspace, said transparent annular inner wall, and said fluid passageway,and heating fluid in said fluid passageway by conduction; wherein saidtransparent annular inner wall is formed in an approximatelysemispherical shape with a concave recess therein, and wherein saidinfrared radiation heating member is U-shaped with at least a portionthereof being positioned in said concave recess.
 14. A fluid heatingdevice in accordance with claim 13, further comprising a housingenclosing said transparent annular inner wall and said annular outerwall, and an elastic supporting member on said housing for supportingboth ends of said U-shaped infrared radiation heating member.